All beer drinking scheduled time limits do not apply to fishing trips and NHCs. It says so right in the rules.
I work in a tackle store next to a fishing area, and when I first started I was surprised how many people start drinking at 6am. I tend to see a lot more wake-and-bake than drinking, though.
I usually have a beer or two while brewing, regardless of the time I brew, but when you own/run a business, you're basically always on the clock. If I never drank when I have a few spare hours at random times, I'd never be able to drink.